Governing means for elastic-fluid turbines



Oct. 1-2;, 1926.

1,603,081 K. M. HOLT GOVERNING MEANS FOR ELASTIC FLUID TURBINES llll Filed Feb. 1'9, 925

ill! \mmunmf w ITwv entO Klate M .l-fiol v Hi Attorney.

I for'ex ainple.

KLATE M. Horn-or mmfmssrcmsms; Ass rG NoR 'ro GENERAL ELECTRIC COM- QPA Y, AfooRroRAtrIoN on NEW: YORK.

minim se Mame roam-immu e 'rURBINEs.

j aai faa ma as, i925; SeriaINo. 1o,3s5.-

The present invention relates to elastic fluid prime movers and more particularly to a means for regulating such prime moversin accordance with Wide Variations. ,-load, 5 inlet pressure, exhaust or back pressure or speed whereby the loadQr'nay be carried with maximum efliciency under such operating conditions, I l The object of. theiinvention is to. provide simple. and effective means in connection with an) elastic fluid turbine for aut omati- F cally meeting operating conditions of the .cliaracterabove named. r

Tlie operating governor of turbinein' connection with the throttle valve is de signed to control the turbine within certain limits and usually serves to maintain substantially a constant speed throughout the I load range. Within. certain limits it oper+ 2O wrninor' changes in the inlet pressure and backipressure also and may be adjusted to give a considerable variation in speed for a given load. It serves thusto "control the turbineover a n'ormal operating range and under substantially normal. operating conditype Whichis contained in a valve casing 18 tions. v I For abnormal 7 operation involving Wide variations in load, inlet pressure, back pressure, or speed beyond the normalrange, the

inlet nozzle area, designed forefficientlop -Q erationjwithinthe normalrange, servesto I I p normal speed causingthe throttle valve to limitthe efli-ciency andfails to admit the additional voluine'of elastic fluid necessary' to compensate for great-1y?increasediback p essure or In accordance with the. invention, this limitation is removed "and the inletnozzle .ance with" the variableQfactor to be compensatedior while providing atthe same'tiine for normal operation, andcontrol by theop crating governor throughout the normal and abnormaloperation'.

The operating conditionmost often toibe met i's that involving a varying j exhaust 1 or back pressure-For thislreason thejiiivenQ tioniis herein described. and illustrated in connection with a turbine which is required" to operate witlrs'uch.varying' backpressure,

ates to admit elastic-fluid in accordance with V greatly. decreased inlet pressure 1 usual methodof speedcontrol and thearjrangement shown ismerely illustrative of area is automatically controlled in accordand -forja 'further consideration of What is I believed to be novel and the inventionpat I tention is nowdirected to tl1e accompanylng drawing, description thereof and the apu pended claims.

In the drawing, Fig. 1 is a viewin side elevation and partly in'section; of a small elastic fluid turbine embodying the inven' tion, and Fig... 2' is an enlarged sectional view'ofa detail thereof.

Reierring to Fig. 1, 5 is which terminates at one end in an exhaust hood provided with an exhaust outlet 7,; and'which at its opposite endis' 'provided' the turbine casing with an elastic fluid inlet chamber 8" having a flanged, inlet opening 9; The inlet cham her is provided with theusual nozzle plate,

"10 through which elastic fluidis directed to V I buckets 11 carried by a fi t Stage bucket Wheel 12. p

The bucket wheel iscarried, togetherwith I those of. succeeding stages'if any, on a shaft 13,]on oneend of which is located a suitable operating or speed governor 14.; This is connectedby a lever 15 and an operating-rod 16 with a, throttle valve .17 of thebala'nced interposed between the flanged inlet opening 9. and anlelastic fluid supply conduit"i19.

The arrangement is such that the governor controls the elastic fluid supply to theturbine, anincrease in speed above acertain' be moved from the full open position shown toward the closedposition in; accordance with such increase in speed. This-lis the onemea-ns for effecting such speed control.

"An emergency valve" 20 is provided in'the :valve casing between thethrottlevalve-ianda a shortconduit 2l leading from the interior ofthe valve casing to theinlet opening f by cutting turbine. c v

The a'rrangement thus far described may.

off the elastic fluid'supply to the be taken as representing any elastic fluid turbine, which 1 is provided with suitable .This arovides for assin an increased volv ume of elastic fluid through the turbine under such conditions, thereby compensating for the decreased pressure ditlerence between the inlet and exhaust and permitting the turbine to carry its load and rated speed.

In the present'example, an additional or auxiliary inlet, nozzle plate 23 is provided for this purpose, together with an auxiliary inlet chamber 24 connected therewith, being substantially a duplicate of the mainnozzle platelO and inlet chamber 8 for said stage.

The auxiliary inlet chamber 24 is connect ed through a branch conduit 25 with conduit 21 between the valve casing 18 and the inlet opening '9 for the main inlet chamber. It thus receives elastic fluid rom the main elastic fluid stream at a point on the delivery or turbine side of the tl'irottlevalve in the same manneras the main inlet chamber. The conduitQl and the branch conduit through which said inlet chambers are sup plied, form the legs of a divided inlet conduit for the turbine, and as both conduits are connected to the delivery or turbine. side of the throttle valve, the flow of elastic fluid through them is at. all times under control of the latter. 7

Theconnection between the auxiliary in let chamber 24 and conduit 21 is controlled by a valve 26 located in the branch conduit 25 and provided with a casing 52'? ntegral therewith. lhis valve is normally closed and is operated y a pressure responsive control-ling device 28- which is shown in detail in Fig. 2. 7

Referring to Figs. 1 andQ, the pressureresponsive device comprises a diaphragm casing 29', a pilot valve casing 30' and an op-. erating cylinder 31, all integral with each other and mounted on a base 32. The base is supported above the valve casing 27' on a threaded valve bonnet 33 with which it is connected by integral webs 34. 'The arrangement is such that a valve stem 35, with which the valve is provided, extends directly up into the cylinder 81 coaxially therewith.

The valve stem is axially slidable to open and close the valve 26' and is suitably guided in its movement in passing through the cap 33 and by a bearing 36 integral with the base 32. lhe valve stem is connected with an operating piston or movable abutment 37 The abutme mentand provides a'shoulder 39 beneath said abutment, and a clamping nut 40 which is threaded onto the reduced end 38 and firmly seats the abutment again-st the shoulder.

' I s shown in its lowermost or normal operating position in which. the valve 26 i's held'irr the closed position. A. coiled spring 41, which surrounds the bear ing 36 and which is'compressed between the lower side of the abutment 37 and the base 32 biases the abutment upwardly to open the valve. By this means the valve is rendered self opening.

The interior of the cylinder 31. above the abutment 37 is connected with the interior of the pilot valve casing 30 by a passage 42. Opposite the passage 42 and spaced apart with respect thereto substantially equally along the length of the pilot valve casing are two openings through the wall, thereof, to which openings are connected conduits 4? and 44. l s

Operatingv fluid under pressure from any suitable source, such as oilfrom the pressure oiling system-of the turbine for example, is

supplied to the pilot valve casing through conduit 43, while conduit 44 serves as a dis-- charge outlet for said operating fluid.

Within the casing 30 is a cylindrical pilot valve 45 which is slidable in and closely fits the interior of the casing. Between the ends of the pilot valve" is a reduced section 45 which provides an annular .passage47 aboutv it of suiiicient length to connect the opening for conduit 43 with the passage 42 when said" pilot valve is in the position shown. In: this positiontheend of the, outlet-conduit 44 is closed by the. body of the pilot valve. i

The pilot valve is movable between the position shown and a certain lower position for conduit 43 and the annular passage 4? connects the passage 42 with the opening for outlet conduit 44. The pilotvalVe is moved from one ofsaid positions to the other under control of a flexible pressure responsive diaphragm 48 within the Qdia 49 and aclamping nut 51 threaded thereon, after the manner of the connection between theabutment 37 and the valverod 35.

Tl'ie diaphragm is suiiici'ently flexible to wherein the body thereof closes the opening,

carry the "pilot valve between its above mentioned positions, but is prevented from carrying said valve beyond these positions by suitable stopnieans located in theidiartegralwiththe casing providing an upper and aloWer seat respectively for the dia-' phragm casing 29., In the present example these comprise a ring 52 and a boss 53-inline leads ,to the interior of the exhaust hood 6- therebyv admitting the exhaust or pressure above the; diaphragm and placing theilatter under the controltliei-eof. .The: ring 52 is of sufficient depth .to preventi'the;

nut '51 from obstructing the opening 54 u when the diaphragm'is seated against said '20 a ring as shown. c The diaphragm desired range-in back pressure -by-Lloading In. the present example atmospheric pressure s'admittedto'tlie lower side ofthe diaphragm age from the pilot; valve. The lower end of the pilot valve casing is 3,180 provided with a .drainpoutlet 157 tofyvhi'ch is connectthat the turbine is operating normally at exhaustlpressures below atmospheric pressure, the diaphragm Will be deflected to the position shown by the differential pressure. This Will carry the pilot valve, as shown,

ed the interior of the cylinder 31 bel.oiv tlie movable abutment thisconnection beingv provided by an opening 58 through the' wall between the cylinderjand the pilot valve cas-j ing. This opening, together withltlie drain outlet 57, serves to vent the loivei' side of the movable abutnient, tliereby rendering it freely movable in the cylinde The operation ofthe present'embodime-nt of the invention is as itollovvszAssuming to the upper position in which it cuts Iofl the outlet conduit'44 and permits operating' fluid to flow from the inlet conduit 43 through passage 42 and into '31 above the abutment 37. i i

The pressure of the Operatingfluid is such that it forces the abutment downward ly against' the elastic fluid pressure existing beneath the valve .26 and against the 1 action; of spring 41, and carries the valve to-the closed position in Which it is shown;

The turbine then receives elastic fluid under, control ofits operating governor throug'l Y the inlet chamber 8 and main inlet' nozzlev plate 10, While the increased inlet are'a pro j vided by the auxiliary inlet nozzle plate [28 in inlet chamber 24 is out oti'. Thenior mal operation for which theturbineis de-- signed is thus una'tlected by the auxiliary the cylinder inlet means and control therefor, and car-- ried on Withmaximum efficiency; ressure increase. by

si-tion This closes the inlet .end fof con- "downvvardly against the stop boss 53, thereby carrying the pilot valve toits lower poc duit 4:3, "thereby fic itting ofi tliepressure.

outlet conduitgM. v Upon the release of the pressure the valve 28" vvill. immediately be opened' byv the' 'action or; the sprineg ll and the elastiejfluid pressure beneath the valve.

the-4abutmentWill be, forced out by Way, of passage. 42 and outleticonduit .44, the spring a i v beingof suiiicient .strenoth-in'itself to is made responsive to any do this and to overcome the Weight of the with any friction that may exist.

iliary inlet nozzle pl'ate, asithe elastic fluid wpressure necessitating a further increase in supply and connecting passage .42 vvith'the Tliejoperating efluid "in the e cylinder above I I abutment, valve and; valve stem, together or, biasing the diaphragm n one d rection I i Y Y or the other by, suitable ;means'. 25

now flows through bothlegs of the divided,

inlet conduit, that is, to-both the main inlet- I chamber' S andthe auxiliary inlet chamber. 24; Theadditional'inletarea is suchthat theturbine'is permitted to receive theneces-LL saryf volume fof elastic fluid to i carry its rated load with maximum eliiciencv against the increased back pressure, It Willbe seen thatfor an additional increase inexhaust q the inlet nozzle area, a'secondauxiliary n,oz-' zle plate 1may be -provided and controlled in asimilar manner. L

By the arrangement provided, the addi-l tional inlet nozzle area, as'ivell as themain. '7

inlet 'nozzle area, is --un der. control, of the operating governor, thus permittingfthetur bine'to operate with the increa'sed exhaust normally; v v

Normal operation is resumed vvhen th'e exhaustpressure falls below atmospheric pressure and sets up a differential pressure on the diaphragm sufficient to return'it to 'theposition; shown. I The operating" fluid pilot valve. and valve-'26 is moved to the closedposition. n 1 y f fln caselitis: desirable to put the auxiliary inlet area into and out of operation betwe en close limits in the diiferential exhaust pressure, the diaphragm may be loaded wither against the exhaust pressure, under that for this purpose, sources ,1 of pressure other'than the atmosphere may be connected pressure beneath the diaphrag v While the invention has been described in pressure in the same manner as it vvould certain conditions, and it vvill be'appreciated V thengadmitted to the cylinder 81- through the 3 J with the inlet-opening 56 vto supply'suitable 1 connection With What. is at. present consid ered to represent the best embodiment there- 'of, it should be understood that the appa- 'ratus shown-is merely illustrative and that the invention maybe carried out by other means. i

lVhat I claim as new and desire to secure by Letters Patent ot the United States, is: 1. The con-ibinzu-ion with an elastic fluid turbine, of means pro-vidinga normal elastic fluid inlet area'tor the initial-pressure stagethereof, means prov ding an additional elas-.

tic fluid inlet area for said initial pressure stage, a main elastic fluid supply conduit for the turbine connected with said first named -means, a branch conduit connecting? the supply conduit with the second named means, a throttle valve in the main supply conduit, means for regulating said valve, a valve in the branch conduit, and means responsive to changes in the turbine exhaust pressure connected with and controlling said last named valve. g I p 2. The combination with an elastic-fluid turbine having a throttle'valve, an operating a jdiv-ided inlet conduit through which elastic fluid is delivered to the turbine from the throttle valve, a valve 111 one leg of said conduit, said valve being self-closing, and pressure-respons1ve means connected with said valve and controlled bv the pressure in the exhaust hood, which means operates to hold the valve in the closed position when said pressure is Within a certain normal operating range. V

l. The combination with an elastic-fluid turbine having a throttle valve, governing means controlling said valve, and means providing a certain normal elastic fluid inlet:

area for the turbine, of means providing an additional elastic fluid inlet area for the turbine, a conduit connecting said means with the throttle valve ad acent the turbine, a valve in said conduit, and means responsive to the exhaust pressure of the turbine connected with and controlling said valve.

5. The combination with an elastic-fluid turbine having a throttle valve, governing ineans controlling said valve, and means providing a certain normal elastic fluid inlet area for the turbine, of means providing an additional elastic fluid inlet area for the turbine, a conduit connecting said means with the throttle valve adjacent the turbine, a valve in said conduit, and means responsive to the exhaust pressure 01" the turbine connected with and controlling said valve, a cer-' tain lower exhaust pressure causing said'device to close the valve and a certain higher IsllllllSil pressure causing said device to open the valve. 7 v

In witness whereof, I have hereunto set my hand this 17th day of February, 1925.

KLATE M. HOLT. 

